正负旋四频差动激光陀螺是一种除反射片外腔内无光学元件的新型四频差动陀螺,其激光工作模式为椭圆偏振本征模。为研究其工作特性,以椭圆偏振模式为本征模,从兰姆半经典自洽场理论出发,结合密度矩阵运动方程,采用三阶微扰处理方法,得出了椭圆偏振模式下的兰姆系数。分析表明,圆偏振本征模下的兰姆系数经加权后可得到椭圆偏振本征模下的兰姆系数,权重是正/负旋圆偏振模电场强度分量大小占椭圆偏振模总电场强度大小比重的平方。由此建立了正负旋四频差动激光陀螺矢量自洽方程组,初步实验验证了理论公式的有效性,可用来对正负旋四频差动激光陀螺进行理论研究。

The positive-negative circularly polarized four-frequency differential laser gyro (PNDLG) is a novel four-frequency differential laser gyro,it has no optical element except the reflecting mirrors in the cavity,its operating modes are elliptical polarization modes. For the study of PNDLG operating characteristics,the vector self-consistency equations of PNDLG are presented with the elliptical polarization eigenvector mode. Based on the Lamb semi-classical self-consistency field theory,the Lamb coefficients of elliptical polarization modes arederived from the motion equations of the density matrix with the third-order perturbation method. The analysis shows that,Lamb coefficients of elliptical polarization modes can be obtained by those of circular polarization modes multiplying the corresponding ratio,the ratio is the square of the proportion of the positive negative circular polarization electric field component to the whole elliptical polarization electric field amplitude. Finally,the vector self-consistency equations of the PNDLG are built up and proved to be effective by the preliminary experiment,which is useful for the theoretical research on the PNDLG.